User blog:Samuli.seppanen/Regarding location of the release mechanism
Today, while writing an article, I realized something. When the cheiroballistra manuscript discusses the release mechanism it does not actually state that the measurements should be taken from the end of the slider (i.e. beam ΓΔ). The assembly instructions start with installing the handle to the slider and continue by detailing how the claw is attached to the fork. Then 5 dactyls, ΔΟ, is measured on board ΓΔ (slider) and rectangular hole pierced through it. Then the tenon in the fork is lowered to Ο. Also, the distance between the axles of the handle and the trigger ("little dragon"), ΜΠ, is given as 4 dactyls. The distance from the handle to one of pittarion's feet (ΞΡ) is not given, but the reference point is still the handle axle. The point is that nowhere is it said that the handle's axle, ΜΝ, or the rectangular hole, Ξ, should be at the end of the slider. All the measurements given are relative to the location of the handle axle, not explicitly from the end of the slider (ΓΔ). One could argue that the manuscript images contradict my claim: However, consider these claims: *At the top, the slider ends at the horizontal line *At the top, the case ends at the horizontal line *At the bottom, the case ends at the horizontal line These are obviously not true. So why should the claim "at the bottom, the slider ends at the horizontal line" be any more true? It seems like this has been the underlying assumption for many, including me until now. I now think the horizontal lines are simply a convention: the diagram looks much nicer if all objects have clear borders, especially when they are colored. The handle, regardless of whether it is seen as something you actively pull with your hands, just use to lock the slider into the case at full draw, or use as an attachment point for a winch, has to withstand lots of strain. As nobody has suggested that the slider was made from anything but wood, placing the handle's axle at the very end of the slider is a very bad idea. Instead of inventing extra components in form of metal reinforcements it makes sense to place the handle some distance from the end of the slider. When the assumption that the handle's axle should be at the very end of the slider is dropped, several problems disappear immediately: *The maximum draw length of the cheiroballistra is reduced somewhat (~2 dactyls) **It is easier/possible to reach full draw without lots of stack **Cones are less likely to pop out of the torsion springs at full draw *One does not have to adjust the measurements to move the handle into a safer place. That said, I don't see this affecting my own reconstruction, as rebuilding the slider and reassembling the triggering mechanism is really low priority for me at the moment. And I don't see any gains in doing that. Category:Blog posts Category:Backup Category:Case and slider Category:Lock